Cat 3116 diesel engines require the proper tools when making any adjustments. One tool that is required is the injector seating tool. This diesel engine has unit style injectors that are seated into cups in the cylinder head.
If you don't properly seat the injectors when replacing or re-installing there is a possibility of compression blow-by which will pressurize the fuel system. I talked about this in a previous post, the fuel tank will build up pressure and your diesel engine will run verrry rough!
I experienced this first hand because I did not seat the injectors at all and relied on the injector hold-down clamps. This caused a lot of extra work, so our shop invested in the hold-down kit 'Cat # 173-1530'
Also when installing the injectors I use the sealing o-ring that fits over the injector tip [not specified for new injectors] this adds to the injector sealing capabilities.
The Cat 3116 seating tool is easy to use [it comes with an instruction manual] Just fit it over the installed injector [injector hold-down clamp torqued] then torque seating tool to 25 ft. lbs wait then retorque. Retorque injector hold-down clamp to 9 ft. lbs. [+ or - 2 ft. lbs.]
I highly recommend the seating tool for any of you doing your own repairs on a 3116 Diesel Engine.